Medical device with support member

ABSTRACT

The invention provides design, material, manufacturing method, and use alternatives for medical devices. An example medical device includes an elongate shaft having a distal region and a coil disposed along the distal region. The coil is formed from a winding member having a first filar region and a second filar region. The winding member has a first cross-sectional diameter along the first filar region, a second cross-sectional diameter different from the first cross-sectional diameter along the second filar region, a first centroid at a first position along the first filar region and a second centroid at a second position along the second filar region. The first centroid and the second centroid are axially-aligned.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/817,903, filed Aug. 4, 2015, which claims priority under 35 U.S.C. §119 to U.S. Provisional Application Ser. No. 62/040,251, filed Aug. 21,2014, the entirety of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure pertains to medical devices, and methods formanufacturing medical devices. More particularly, the present disclosurepertains to elongated intracorporeal medical devices including a tubularmember connected with other structures, and methods for manufacturingand using such devices.

BACKGROUND

A wide variety of intracorporeal medical devices have been developed formedical use, for example, intravascular use. Some of these devicesinclude guidewires, catheters, and the like. These devices aremanufactured by any one of a variety of different manufacturing methodsand may be used according to any one of a variety of methods. Of theknown medical devices and methods, each has certain advantages anddisadvantages. There is an ongoing need to provide alternative medicaldevices as well as alternative methods for manufacturing and usingmedical devices.

BRIEF SUMMARY

This disclosure provides design, material, manufacturing method, and usealternatives for medical devices. An example medical device includes anelongate shaft having a distal region and a coil disposed along thedistal region. The coil is formed from a winding member having a firstfilar region and a second filar region. The winding member has a firstcross-sectional diameter along the first filar region, a secondcross-sectional diameter different from the first cross-sectionaldiameter along the second filar region, a first centroid at a firstposition along the first filar region and a second centroid at a secondposition along the second filar region. Further, the first centroid andthe second centroid are axially-aligned.

Alternatively or additionally to any of the examples above, in anotherexample the first filar region includes a first filar inside diameterand the second filar region includes a second filar inside diameter andthe first filar inside diameter is different from the second filarinside diameter.

Alternatively or additionally to any of the examples above, the windingmember includes a first pitch in the first filar region and the windingmember includes a second pitch in the second filar region, and the firstpitch is different than the second pitch.

Alternatively or additionally to any of the examples above, the firstpitch is approximately equal to the first cross-section diameter.

Alternatively or additionally to any of the examples above, the coilincludes an outer layer.

Alternatively or additionally to any of the examples above, the outerlayer substantially surrounds the winding member of the second filarregion.

Alternatively or additionally to any of the examples above, the outerlayer is capable of altering the flexibility of the first filar region,the second filar region, or both.

Alternatively or additionally to any of the examples above, the firstfilar region has a first flexibility and the second filar region has asecond flexibility and the first flexibility is different from thesecond flexibility.

Alternatively or additionally to any of the examples above, the windingmember has a first outer diameter along the first filar region, and thewinding member has a second outer diameter different from the firstouter diameter along the second filar region.

Alternatively or additionally to any of the examples above, the firstfilar region includes a first filar inside diameter and the second filarregion includes a second filar inside diameter and the first filarinside diameter is different from the second filar inside diameter.

Alternatively or additionally to any of the examples above, the windingmember includes one or more filars.

Alternatively or additionally to any of the examples above, the outerlayer includes a proximal outer diameter and a distal outer diameter,and the proximal outer diameter is greater than the distal outerdiameter.

Alternatively or additionally to any of the examples above, the firstouter diameter of the first filar region is greater than the secondouter diameter of the second filar region.

Alternatively or additionally to any of the examples above, the firstouter diameter of the first filar region and the second outer diameterof the second filar region decrease step-wise.

Alternatively or additionally to any of the examples above, the outerlayer includes a proximal portion and a distal portion, and the outerlayer is tapered from the proximal portion to the distal portion.

An example method for manufacturing a medical device includes disposinga coil in a processing solution. The coil is formed from a filar havinga cross-sectional diameter. Disposing a coil in a processing solutionreduces the cross-sectional diameter of at least a portion of the filar.The method also includes disposing the processed coil along a cathetershaft and securing the coil to the catheter shaft.

Alternatively or additionally to any of the examples above, theprocessing solution includes acid etching, electropolishing, or both.

Alternatively or additionally to any of the examples above, disposingthe coil in the processing solution further includes defining theduration the coil is dipped, the temperature of the processing solution,or both.

Alternatively or additionally to any of the examples above, the filarhas a first filar region and a second filar region, and wherein thefirst filar region includes a first filar inside diameter and the secondfilar region includes a second filar inside diameter and the first filarinside diameter is different from the second filar inside diameter.

Alternatively or additionally to any of the examples above, the firstfilar region has a first centroid and the second filar region has asecond centroid, and the first centroid is axially-aligned with thesecond centroid.

Alternatively or additionally to any of the examples above, the firstfilar region includes a first pitch and the second filar region includesa second pitch, and the first pitch is different from the second pitch.

Alternatively or additionally to any of the examples above, the coil hasan outer diameter and reducing the cross-sectional diameter of at leasta portion of the filar includes reducing the outer diameter of the coil.

Alternatively or additionally to any of the examples above, securing thecoil to the catheter shaft includes disposing a sleeve on the coil.

Alternatively or additionally to any of the examples above, securing thecoil to the catheter shaft includes embedding the coil in a coating.

Another example medical device includes a catheter including an innerelongate layer, a coil, and an outer elongate layer. The coil isdisposed between the inner layer and the outer layer. The coil defines adistal winding region. The distal winding region includes a first filarregion and a second filar region, and the coil has a first cross-sectiondiameter along the first filar region and the coil has secondcross-section diameter different from the first cross-section diameteralong the second filar region and the outer layer substantiallysurrounds the coil along the second filar region.

The above summary of some embodiments is not intended to describe eachdisclosed embodiment or every implementation of the present disclosure.The Figures, and Detailed Description, which follow, more particularlyexemplify these embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure may be more completely understood in consideration of thefollowing detailed description in connection with the accompanyingdrawings, in which:

FIG. 1 is a plan view of an embodiment of a medical device according tothe invention disposed in a blood vessel;

FIG. 2 is an embodiment of a medical device according to the invention;

FIG. 3 is a cross-sectional view of a support member useful in theinvention;

FIG. 4 is a cross-sectional view of a support member useful in theinvention showing a reduction in the diameter of the support member;

FIG. 5 is a cross-sectional view of a multi-strand wire useful in theinvention showing a reduction in the diameter of each strand of themulti-strand wire;

FIG. 5a is a side-view of an example multi-strand wire showing flattenedcross-sections of individual filars;

FIG. 5b is a side-view of a multi-strand, multi-layer wire showingflattened cross-sections of individual filars;

FIG. 6 is a cross-sectional view of a wire disposed over a tubularmember;

FIG. 7 is a cross-sectional view of a wire disposed between a tubularmember and an outer layer;

FIG. 8 is a cross-sectional view of a wire embedded in an outer layer;

FIG. 9 is a cross-sectional view of a wire disposed over a tubularmember and a tapered outer layer;

FIG. 10 is a cross-sectional view of a wire incorporated into a medicaldevice.

While the disclosure is amenable to various modifications andalternative forms, specifics thereof have been shown by way of examplein the drawings and will be described in detail. It should beunderstood, however, that the intention is not to limit the invention tothe particular embodiments described. On the contrary, the intention isto cover all modifications, equivalents, and alternatives falling withinthe scope of the disclosure.

DETAILED DESCRIPTION

For the following defined terms, these definitions shall be applied,unless a different definition is given in the claims or elsewhere inthis specification. All numeric values are herein assumed to be modifiedby the term “about,” whether or not explicitly indicated. The term“about” generally refers to a range of numbers that one of skill in theart would consider equivalent to the recited value (i.e., having thesame function or result). In many instances, the terms “about” mayinclude numbers that are rounded to the nearest significant figure.

The recitation of numerical ranges by endpoints includes all numberswithin that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and5).

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include plural referents unless the contentclearly dictates otherwise. As used in this specification and theappended claims, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

It is noted that references in the specification to “an embodiment”,“some embodiments”, “other embodiments”, etc., indicate that theembodiment described may include one or more particular features,structures, and/or characteristics. However, such recitations do notnecessarily mean that all embodiments include the particular features,structures, and/or characteristics. Additionally, when particularfeatures, structures, and/or characteristics are described in connectionwith one embodiment, it should be understood that such features,structures, and/or characteristics may also be used connection withother embodiments whether or not explicitly described unless clearlystated to the contrary.

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The drawings, which are not necessarily to scale, depictillustrative embodiments and are not intended to limit the scope of theinvention.

FIG. 1 is a plan view of an embodiment of a medical device 10, forexample a guidewire, disposed in a blood vessel 12. Guidewire 10 mayinclude a distal section 14 that may be generally configured for probingwithin the anatomy of a patient. Guidewire 10 may be used forintravascular procedures. For example, guidewire 10 may be used inconjunction with another medical device 16, which may take the form of acatheter, to treat and/or diagnose a medical condition. Of course,numerous other uses are known amongst clinicians for guidewires,catheters, and other similarly configured medical devices.

Although medical device 10 is depicted in FIG. 1 as a guidewire, it isnot intended to be limited to just being a guidewire. Indeed, medicaldevice 10 may take the form of other suitable guiding, diagnosing, ortreating device (including catheters, endoscopic instruments,laparoscopic instruments, etc., and the like) and it may be suitable foruse at other locations and/or body lumens within a patient. For example,FIG. 2 illustrates an embodiment of device 16 in the form of a catheter.Catheter 16 may include a generally elongate shaft 22 having a proximalportion 13 and a distal portion 15. A proximal manifold 17 may bedisposed at proximal portion 13. Manifold 17 may include a hub 20 andstrain relief 11.

Because of their intended use in the vasculature, some medical devicesare designed to have particular physical characteristics such asflexibility (e.g., for the purposes of this disclosure, flexibility maybe also be termed or expressed as bending stiffness or flexuralrigidity). For example, some medical devices may be designed to be verystiff in order to provide enough columnar strength to navigateanatomical areas of resistance. Alternatively, some medical devices maybe designed flexible enough in order to bend in a manner sufficient totraverse tortuous anatomy. Therefore, at the distal end of the medicaldevice, it may be desirable to tailor the flexibility of the medicaldevice so that the device can effectively reach its target within thevasculature. For example, in order to reach coronary vessels and/orvessels near the heart a guidewire may be designed to be relativelyflexible at the distal end. However, if the flexibility is too great,the guidewire may not efficiently turn nor maintain the ability tonegotiate a blocked passageway, but instead, may have a tendency tobuckle upon itself. Thus, tailoring the flexibility at the distal end ofa guidewire so that it is able to efficiently advance through tortuousanatomy while minimizing the likelihood that the guidewire will buckleback upon itself may be desirable.

In some instances it may be desirable to combine different structuralcomponents in order to achieve the desired flexibility and stiffnesscharacteristics of a guidewire. For example, it may be desirable tocombine (e.g. weld, melt, bond, etc.) one or more different shaftconfigurations (e.g. different materials, dimensions, etc.) and/or coilconfigurations with one another to achieve a desired performance output.However, combining different structural components may require a longerand more complex manufacturing process. Therefore, in some instances itmay be desirable to tailor and integrate single-piece components into afinished medical device in order that they exhibit desired performanceproperties. For example, removing material from a single-piece cathetershaft or coil may provide the same benefit as combining two or morenon-tailored components. The tailored component may then be integratedinto the overall catheter design.

FIG. 3 shows an embodiment of a support member 26 that may be utilizedin catheter 16 and/or other devices disclosed herein. In thisembodiment, support member 26 may take the form of a coil. However, inother embodiments, support member 26 may take the form of a braid orother support member. Coil 26 may include one or more filars 28. Forpurposes of this discussion, a “filar” may be understood as a wire orwires that are wound into a coiled configuration in order to form orotherwise define coil 26. As can be seen in FIG. 3, filar 28 may have auniform cross-sectional diameter and pitch. While a uniformcross-sectional diameter is shown in FIG. 3, it is contemplated that thecross-sectional diameter of filar 28 may vary across the length of coil26. Additionally, coil 26 may be configured to have an open pitch, aclosed pitch or combinations thereof. For example, FIG. 3 shows filar 28arranged such that there is no space between the individual windings.The absence of space between the windings may be referred to as a“closed” pitch configuration. A closed pitch configuration may bedesirable to provide increased column strength to a given component of amedical device. Further, characteristics such as the filarcross-sectional dimension and/or shape, material, orientation andspacing may contribute to the overall configuration and performance(e.g. flexibility, pushability, trackability, column stiffness, etc.) ofcoil 26.

As stated above, in some instances in may be desirable to perform amanufacturing process to tailor the design configuration of a medicaldevice component. For example, it may be desirable to alter coil 26 inorder to provide the desired flexibility characteristics to catheter 16.For example, it may be desirable to remove material from a distal regionof coil 26. In some instances, the manufacturing process may includedipping coil 26 into a processing solution. The dipping process may bedone for a given length of time and at a given temperature. For example,processing techniques such as acid etching and/or electropolishing maybe utilized, however, similar techniques are contemplated as well. Asstated, the amount of material removed from coil 26 may be influenced bythe type of solution utilized, the temperature of the solution, theconcentration of the solution, the speed/rate at which the coil isdipped, the duration of time the coil is left in the solution, orcombinations thereof. Additionally, after having removed material, theshape of coil 26 may be further refined by manipulating the shape offilar 28. For example, filar 28 may be “re-shaped” by forcing it toconform to a predetermined shape (e.g. by placing it on a mandrel)followed by performing a stress-relief heat treatment.

As seen in FIG. 4, removing material and/or reshaping coil 26 maycorrespond to a change in its dimensions. FIG. 4 shows an embodiment ofcoil 26 after having been processed to remove material from filar 28. Asshown, coil 26 may be constructed from a single, uninterrupted wire,filament, filar, ribbon or the like. In FIG. 4, filar 28 may have acircular cross-sectional shape. The dashed line in FIG. 4 illustratesthat the centroids 38 of filar 28 may be axially-aligned. A centroid 38may be described as the center point of the cross-section of a givenfilar 28. It is also contemplated that the cross-sectional shape offilar 28 may be something other than circular. For example, thecross-sectional shape may be triangular, rectangular, oval, or the like.Non-circular shapes may also have centroids that are axially-aligned.

In some instances, filar 28 may have a first filar region 28 a and asecond filar region 28 b. Additionally, after material has been removedfrom coil 26, filar 28 may have different diameters. For example, FIG. 4shows diameters D1 and D2 of filar region 28 a and 28 b, respectively.As can be seen, diameter D1 of filar region 28 a is greater thandiameter D2 of filar region 28 b. The reduced diameter of filar region28 b may be due to a greater amount of material having been removed fromfilar region 28 b versus filar region 28 a. In addition to the diameterof filar 28, other dimensions may change as a result of materialremoval. For example, FIG. 4 shows ID1 and ID2 corresponding to theinner diameter of coil 26 at filar region 28 a and 28 b, respectively.As shown, inner diameter ID1 of filar region 28 a is less than innerdiameter ID2 of filar region 28 b. The increased inner diameter ID2 offilar region 28 b (as compared to ID1 of filar region 28 a) can becontributed to the reduction in diameter D2 of filar region 28 b (ascompared to D1 of filar region 28 a).

Additionally, the removal of material may create open space betweenadjacent windings of filar 28. For example, removing material from adistal portion may create open pitch portion 32. Open pitch portion 32may be defined as space existing between adjacent windings of filar 28.Depending on the degree to which material is removed, the spacingbetween adjacent windings of filar 28 may vary. For example, FIG. 4shows space S1 located proximal of space S2, both of which are locatedin open pitch portion 32. Further, it can be seen that space S1 is lessthan S2. The increase in space S2 (as compared to S1) can be contributedto the decrease of diameter D2 of filar region 28 b (as compared todiameter D1 of filar region 28 a).

As stated above, removal of material may be the result of dipping coil26 into a processing solution. Therefore, in general, dimensionalchanges and creation of open space between adjacent windings of filar 28may result from the up and down dipping process utilized to removematerial from coil 26 and/or filar 28. It is also contemplated that thedimensional changes and the extent of open space created may beinfluenced by the manner in which the process is performed. For example,in some instances the process may include dipping and holding themedical device in the processing solution. In another example process,the medical device may be dipped and/or withdrawn in a stepwise manner.

For example, the medical device may be dipped and held in the processingsolution for an initial amount of time. During this initial holdingperiod, an initial amount of material may be removed from the portion ofthe medical device subject to the processing solution. After thisinitial holding period, the medical device may be partially withdrawnand held in the processing solution for a second period of time. Duringthe second holding period, additional material may be removed from theportion of the medical device subject to the processing solution. It canbe understood that after the second holding period, the outer diameterof the medical device may be different as a result of additionalmaterial being removed during the second holding period. Further, thisstepwise dipping process may be repeated to achieve the desired stepwisegeometry for the medical device. As stated, the particular processimplemented may influence the final dimensions, spacing, geometry, etc.of coil 26 and/or filar 28.

In addition to open pitch portion 32, coil 26 may include closed pitchportion 30. Closed pitch portion 30 may correspond to the portion ofcoil 26 for which no material is removed during a manufacturing process.For example, closed pitch portion 30 may not have been subjected to thedipping process used to remove material from open pitch portion 32.Because no material has been removed from closed pitch portion 30, nospace has been created between the windings of filar 28 in closedportion 30.

As can be seen in FIG. 4, the space between filar 28 may graduallyincrease from closed pitch portion 30 to the distal end of coil 26. Thegradual increase in pitch (corresponding to a gradual increase in theamount of material removed from filar 28), may correspond to aprogressive change in performance characteristics of coil 26. Forexample, the flexibility of closed pitch portion 30 may differ from thatof open pitch portion 32, due to the dimensional and pitch change offilar 28. Further, the performance characteristics of open cell portionmay gradually change from filar region 28 a to 28 b. For example, theflexibility of open cell portion 32 generally surrounding filar region28 a may be less than the flexibility of closed cell portion 30generally surrounding filar region 28 b.

In some instances, coil 26 may be processed to selectively include orexclude portions of the coil from which material will be removed. Forexample, portions of coil 26 may be selectively “masked,” so that themasked regions of coil 26 are not affected by a material removalmanufacturing process. Additionally, coil 26 may be masked in a mannerthat removes material from different portions of the coil 26 such thatthe performance of the coil 26 is specifically tailored to a specificapplication or performance output.

As an alternative embodiment to coil 26 in FIG. 4, FIG. 5 shows coil126. Similar to coil 26, coil 126 includes filar 128. However, incontrast to filar 28 of FIG. 4, filar 128 may include multiple filarstrands 128 a, 128 b and 128 c. Filar strands 128 a, 128 b and 128 c maybe braided, woven, twisted, interlaced or the like. Additionally, thecentroids of filar 128 of coil 126 may be axially-aligned. Further, asFIG. 5 shows, dimensional changes as a result of material removed fromfilar 128 may be similar to that discussed with respect to FIG. 4 above.

In some instances, a coil may include multiple filar strands arranged ina configuration as shown in FIG. 5a . For example, FIG. 5a shows sixindividual filar strands 428 a-f configured such that the strands areinterwound along the length of coil 426. In this configuration, eachindividual filar 428 a-f has an open pitch (e.g. space between adjacentwindings) such that the open space for a given individual filar may befilled by the remaining filar members. For example, FIG. 5a shows coil426 having six filars, and therefore, an open space defining an openpitch portion may be seen where the space between the windings of eachindividual filar may be filled by the remaining filars. In other words,the spacing between the individual filars may be approximately equal tothe number of filars multiplied by the diameter (or width) of thefilars. In FIG. 5a , therefore, the open pitch portion may be equal tothe diameter of any one of filars 428 a-f multiplied by five. It iscontemplated that a coil arrangement may include more or less than thesix filars disclosed in FIG. 5a . For example, an example coil mayinclude 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or more filars.

Additionally or alternatively, a multiple-filar coil may include filarsmade of different materials and/or having different material properties.Filars constructed of different materials may have different degradationrates and, therefore, different cross-sectional dimensions at a givenpoint in time (e.g., due to different degradation rates). Therefore, acoil having filars made from different materials may exhibit differentcross-sectional dimensions (e.g., due to different degradation rates) atdifferent time points during and/or after the processing of the coil. Inother instances, the multiple filar coil may include materials withsimilar or the same degradation rates such that processing may proceedas described herein.

In some instances it may be desirable to configure the cross-sectionalshape of a given filar to resemble the cross-sectional diameter offilars 428 a-f shown in FIG. 5a . For example, the cross-sectional shapeof filars 428 a-f may be substantially ovular. Other shapes such ascircular, polygonal, or the like are also contemplated. Thecross-sectional shape of filars in FIG. 5a may be manufactured byplacing the coil on a mandrel and applying an external force and/orswagging to flatten filars 428 a-f into the desired (e.g. ovular, etc.)shape.

In addition to the coil configuration described in FIG. 5a , in someinstances it may be desirable to configure a medical device such thatthe coil includes multiple layers. For example, FIG. 5b shows coil 526including an inner coil 530 located inside outer coil 532. As shown, thecross-sectional shape of individual outer coil filars 528 of outer coil532 and inner coil filars 534 of inner coil 530 are configured asdescribed above with respect to filars 428 a-f in FIG. 5a . Similar tothat of coil 426 of FIG. 5a , coil 526 may be manufactured by placingcoil 526 on a mandrel and applying an external force and/or pressure toflatten the individual filars into the desired shape. Additionally,inner and outer coil layers 530/532 may be swaged.

It should be noted that FIGS. 5a-5b disclose coil configurations thatmay be untreated. It is contemplated that after treating coils disclosedin FIGS. 5a-5b , the coils may resemble the treated coil of FIG. 4. Forexample, it is contemplated that the coil configurations in FIGS. 5a-5bmay have material removed, resulting in an open pitch portion. Further,filars associated with such coils may have a variable pitch opening(e.g. pitch opening increases with decreasing filar diameter) betweenadjacent filars. Additionally, the filars may have a constant pitchopening between adjacent filars (e.g. pitch opening remainssubstantially constant as filar diameter decreases). It is alsocontemplated that after treatment of coils disclosed herein, individualfilars may be repositioned such that the desired degree of pitch opening(e.g. constant, variable, etc.) may be obtained.

As suggested herein, it may be desirable to manufacture a number ofdifferent medical devices (e.g., guidewire 10, catheter 16, or the like)in a manner that incorporates coil 26. Doing so may provide a number ofdifferent desirable characteristics to the resultant device. FIGS. 6-8show a portion of an example manufacturing process for manufacturing,for example, catheter 16. In this example, catheter 16 incorporates coil26 into the catheter shaft. The manufacturing process may includedisposing coil 26 over a tubular member or shaft 34. Additionally, coil26 may be placed directly on top of shaft 34. However, it iscontemplated that coil 26 may be disposed over shaft 34 while in atensed state and upon release, coil 26 may “squeeze” down onto shaft 34.In other embodiments, coil 26 may be embedded into shaft 34.

In some instances, shaft 34 may represent a tubular member of catheter16. For example, shaft 34 may represent the inner member of catheter 16.However, while described herein as an inner shaft, it is contemplatedthat shaft 34 may include a variety of tubular members. For example,shaft 34 may include a guidewire, polymer tube, elongate member or thelike. Additionally, it is contemplated that the combination of coil 26and shaft 34 may alter the performance properties of catheter 16. Forexample, the combination of coil 26 and shaft 34 may result in anoptimal balance of catheter stiffness and flexibility.

In addition to that described above, it may be desirable to furthertailor the performance characteristics of catheter 16 by addingadditional materials and/or layers onto existing components. Forexample, FIG. 7 shows example catheter 16 having incorporated coil 26onto shaft 34. Further, FIG. 7 shows an additional manufacturing step ofincorporating an outer layer 36 into catheter 16. Specifically, outerlayer 36 is disposed over coil 26, coil 26 being disposed over shaft 34.In some instances, outer layer 36 may be sit atop coil 26. In otherinstances, however, outer layer 36 may squeeze down and/or pinch coil 26onto shaft 34.

Additionally, outer layer 36 may be one or more polymer and/or plasticmaterials. Further, outer layer 36 may include more than one material.For example, outer layer 36 may include two materials having differentmaterial properties (e.g. durometer, tensile strength, etc.). It is alsounderstood that outer layer 36 may include materials other than polymersor plastics. For example, outer layer 36 may include polymers, metals,ceramics, combinations thereof, and the like.

In some instances it may be desirable to further incorporate outer layer36 with coil 26, sheath 34 or a combination thereof. FIG. 8 shows anexample catheter 16 including coil 26, shaft 34 and outer layer 36.Further, outer layer 36 has been processed such that coil 26 is embeddedwithin sheath 36. Additionally, manufacturing catheter 16 such that coil26 may be embedded in outer layer 36 may require melting and/orreflowing outer layer 36 around coil 26.

As can be seen in FIG. 8, coil 26 may maintain the same configuration asdescribed herein. For example, material may have been progressivelyremoved from filar 28. Further, the centroids of filar 28 may remainaxially-aligned before and after manufacturing outer layer 36 to reflowaround coil 26.

Reconfiguring the components of catheter 16 disclosed herein may resultin different performance outputs. For example, FIG. 9 shows an examplecatheter 216 including coil 226 disposed along shaft 234 and embedded insheath 236. However, as FIG. 9 shows, the centroids of filar 228 may notbe axially-aligned. Rather, the filar 228 of coil 226 may lie along thesurface of shaft 234. In this configuration, the centroid alignment offilar 228 may be tapered with respect to shaft 234. In addition, asshown in FIG. 9, the inner diameter of coil 226 may be substantiallyuniform along the surface of shaft 234. For example, pressure may beapplied to filar 228 in order to shift filar 228 so that the innerdiameter remains uniform.

Further, in some instances it may be desirable to modify the outerprofile of catheter 216. For example, outer layer 236 may be taperedfrom a proximal to distal direction. As shown in FIG. 9, the outerdiameter of proximal portion 210 of catheter 216 is greater than theouter diameter of distal portion 212. However, while FIG. 9 shows outerlayer 236 tapering in from a proximal to distal direction, it iscontemplated that other configurations may be desirable.

FIG. 10 shows example guidewire 310 incorporating coil 326. In someinstances, guidewire 310 may include a radiopaque coil 344 attached to acore wire 340 by a weld 342. Further, a proximal portion of coil 326 maybe attached to core wire 340 and a distal portion of coil 326 may beattached to tip portion 346. Tip portion 346 may also be attached to aribbon 348. Coil 326 may be configured according to any of theembodiments disclosed herein. For example, FIG. 10 shows the centroidsof filar 328 of coil 326 axially-aligned over the length of coil 326. Inother examples, the centroids of the filar 328 may not beaxially-aligned. Additionally, coil 326 may be coated and/or include asheath or covering.

The materials that can be used for the various components of guidewire10 (and/or other guidewires disclosed herein) and the various tubularmembers disclosed herein may include those commonly associated withmedical devices. For simplicity purposes, the following discussion makesreference to catheter 16 and other components of guidewire 10. However,this is not intended to limit the devices and methods described herein,as the discussion may be applied to other similar medical devices and/orcomponents of medical devices disclosed herein.

Catheter 16 and/or other components of guidewire 10 may be made from ametal, metal alloy, polymer (some examples of which are disclosedbelow), a metal-polymer composite, ceramics, combinations thereof, andthe like, or other suitable material. Some examples of suitable metalsand metal alloys include stainless steel, such as 304V, 304L, and 316LVstainless steel; mild steel; nickel-titanium alloy such aslinear-elastic and/or super-elastic nitinol; other nickel alloys such asnickel-chromium-molybdenum alloys (e.g., UNS: N06625 such as INCONEL®625, UNS: N06022 such as HASTELLOY® C -22®, UNS: N10276 such asHASTELLOY® C276®, other HASTELLOY® alloys, and the like), nickel-copperalloys (e.g., UNS: N04400 such as MONEL® 400, NICKELVAC® 400, NICORROS®400, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R30035 such as MP35-N® and the like), nickel-molybdenum alloys (e.g.,UNS: N10665 such as HASTELLOY® ALLOY B2®), other nickel-chromium alloys,other nickel-molybdenum alloys, other nickel-cobalt alloys, othernickel-iron alloys, other nickel-copper alloys, other nickel-tungsten ortungsten alloys, and the like; cobalt-chromium alloys;cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such as ELGILOY®,PHYNOX®, and the like); platinum enriched stainless steel; titanium;combinations thereof; and the like; or any other suitable material.

As alluded to herein, within the family of commercially availablenickel-titanium or nitinol alloys, is a category designated “linearelastic” or “non-super-elastic” which, although may be similar inchemistry to conventional shape memory and super elastic varieties, mayexhibit distinct and useful mechanical properties. Linear elastic and/ornon-super-elastic nitinol may be distinguished from super elasticnitinol in that the linear elastic and/or non-super-elastic nitinol doesnot display a substantial “superelastic plateau” or “flag region” in itsstress/strain curve like super elastic nitinol does. Instead, in thelinear elastic and/or non-super-elastic nitinol, as recoverable strainincreases, the stress continues to increase in a substantially linear,or a somewhat, but not necessarily entirely linear relationship untilplastic deformation begins or at least in a relationship that is morelinear that the super elastic plateau and/or flag region that may beseen with super elastic nitinol. Thus, for the purposes of thisdisclosure linear elastic and/or non-super-elastic nitinol may also betermed “substantially” linear elastic and/or non-super-elastic nitinol.

In some cases, linear elastic and/or non-super-elastic nitinol may alsobe distinguishable from super elastic nitinol in that linear elasticand/or non-super-elastic nitinol may accept up to about 2-5% strainwhile remaining substantially elastic (e.g., before plasticallydeforming) whereas super elastic nitinol may accept up to about 8%strain before plastically deforming. Both of these materials can bedistinguished from other linear elastic materials such as stainlesssteel (that can also can be distinguished based on its composition),which may accept only about 0.2 to 0.44 percent strain beforeplastically deforming.

In some embodiments, the linear elastic and/or non-super-elasticnickel-titanium alloy is an alloy that does not show anymartensite/austenite phase changes that are detectable by differentialscanning calorimetry (DSC) and dynamic metal thermal analysis (DMTA)analysis over a large temperature range. For example, in someembodiments, there may be no martensite/austenite phase changesdetectable by DSC and DMTA analysis in the range of about −60 degreesCelsius (° C.) to about 120° C. in the linear elastic and/ornon-super-elastic nickel-titanium alloy. The mechanical bendingproperties of such material may therefore be generally inert to theeffect of temperature over this very broad range of temperature. In someembodiments, the mechanical bending properties of the linear elasticand/or non-super-elastic nickel-titanium alloy at ambient or roomtemperature are substantially the same as the mechanical properties atbody temperature, for example, in that they do not display asuper-elastic plateau and/or flag region. In other words, across a broadtemperature range, the linear elastic and/or non-super-elasticnickel-titanium alloy maintains its linear elastic and/ornon-super-elastic characteristics and/or properties.

In some embodiments, the linear elastic and/or non-super-elasticnickel-titanium alloy may be in the range of about 50 to about 60 weightpercent nickel, with the remainder being essentially titanium. In someembodiments, the composition is in the range of about 54 to about 57weight percent nickel. One example of a suitable nickel-titanium alloyis FHP-NT alloy commercially available from Furukawa Techno Material Co.of Kanagawa, Japan. Some examples of nickel titanium alloys aredisclosed in U.S. Pat. Nos. 5,238,004 and 6,508,803, which areincorporated herein by reference. Other suitable materials may includeULTANIUM™ (available from Neo-Metrics) and GUM METAL™ (available fromToyota). In some other embodiments, a superelastic alloy, for example asuperelastic nitinol can be used to achieve desired properties.

In at least some embodiments, portions or all of catheter 16 and/orguidewire 10 may also be doped with, made of, or otherwise include aradiopaque material. Radiopaque materials are understood to be materialscapable of producing a relatively bright image on a fluoroscopy screenor another imaging technique during a medical procedure. This relativelybright image aids the user of guidewire 10 in determining its location.Some examples of radiopaque materials can include, but are not limitedto, gold, platinum, palladium, tantalum, tungsten alloy, polymermaterial loaded with a radiopaque filler, and the like. Additionally,other radiopaque marker bands and/or coils may also be incorporated intothe design of guidewire 10 to achieve the same result.

In some embodiments, a degree of Magnetic Resonance Imaging (MRI)compatibility is imparted into guidewire 10. For example, catheter 16and/or guidewire 10, or portions thereof, may be made of a material thatdoes not substantially distort the image and create substantialartifacts (i.e., gaps in the image). Certain ferromagnetic materials,for example, may not be suitable because they may create artifacts in anMRI image. Catheter 16 and/or guidewire 10, or portions thereof, mayalso be made from a material that the MRI machine can image. Somematerials that exhibit these characteristics include, for example,tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such asELGILOY®, PHYNOX®, and the like), nickel-cobalt-chromium-molybdenumalloys (e.g., UNS: R30035 such as MP35-N® and the like), nitinol, andthe like, and others.

It should be understood that this disclosure is, in many respects, onlyillustrative. Changes may be made in details, particularly in matters ofshape, size, and arrangement of steps without exceeding the scope of thedisclosure. This may include, to the extent that it is appropriate, theuse of any of the features of one example embodiment being used in otherembodiments. The invention's scope is, of course, defined in thelanguage in which the appended claims are expressed.

What is claimed is:
 1. A catheter comprising: a tubular elongate shafthaving a distal region and a lumen extending therethrough; a coilsurrounding an outer surface of the distal region of the tubularelongate shaft, wherein the coil is formed from one or more filarsforming a plurality of windings; wherein the coil has a first filarregion and a second filar region, the first filar region extending to aproximal end of the coil, and the second filar region extending to adistal end of the coil; wherein each filar of the one or more filars hasa first cross-sectional diameter along the first filar region and asecond cross-sectional diameter along the second filar region, thesecond cross-sectional diameter being less than the firstcross-sectional diameter; wherein each filar of the one or more filarshas a cross-sectional area having a first centroid at a first positionalong the first filar region and a cross-sectional area having a secondcentroid at a second position along the second filar region, the secondcentroid being positioned closer to a central longitudinal axis of thetubular elongate shaft than the first centroid; wherein the coil has aclosed pitch in the first filar region in which there is no spacebetween adjacent windings of the plurality of windings, and the coil hasan open pitch in the second filar region in which there is spacingbetween adjacent windings of the plurality of windings; and wherein thespacing between adjacent windings of the plurality of windings increasesin a distal direction along the second filar region; wherein a firstlongitudinal distance between centroids of adjacent windings of theplurality of windings in the first filar region is equal to a secondlongitudinal distance between centroids of adjacent windings of theplurality of windings in the second filar reqion.
 2. The catheter ofclaim 1, wherein each winding contacts the outer surface of the tubularelongate shaft.
 3. The catheter of claim 1, wherein a first radialdistance between the central longitudinal axis and the first filarregion is the same as a second radial distance between the centrallongitudinal axis and the second filar region.
 4. The catheter of claim1, further comprising a polymeric outer layer surrounding and in contactwith the coil.
 5. The catheter of claim 4, wherein the one or morefilars are embedded in the polymeric outer layer in the second filarregion.
 6. The catheter of claim 5, wherein the polymeric outer layerhas an outer diameter that tapers radially inward in a distal directionalong the second filar region.
 7. The catheter of claim 5, wherein thepolymeric outer layer contacts the tubular elongate shaft betweenadjacent windings of the plurality of windings in the second filarregion.
 8. The catheter of claim 1, wherein the coil has a first outerdiameter along the first filar region and a second outer diameter alongthe second filar region, the second outer diameter being less than thefirst outer diameter.
 9. A catheter, comprising: a tubular elongateshaft having a distal region and a lumen extending therethrough; a coilsurrounding an outer surface of the distal region of the tubularelongate shaft, wherein the coil is formed from one or more filarsforming a plurality of windings; wherein the coil has a first filarregion and a second filar region, the first filar region extending to aproximal end of the coil, and the second filar region extending to adistal end of the coil; wherein each filar of the one or more filars hasa first cross-sectional diameter along the first filar region and asecond cross-sectional diameter along the second filar region, thesecond cross-sectional diameter being less than the firstcross-sectional diameter; wherein each filar of the one or more filarshas a cross-sectional area having a first centroid at a first positionalong the first filar region and a cross-sectional area having a secondcentroid at a second position along the second filar region, wherein afirst longitudinal distance between centroids of adjacent windings ofthe plurality of windings in the first filar region is equal to a secondlongitudinal distance between centroids of adjacent windings of theplurality of windings in the second filar region; wherein the coil has aclosed pitch in the first filar region in which there is no spacebetween adjacent windings of the plurality of windings, and the coil hasan open pitch in the second filar region in which there is spacingbetween adjacent windings of the plurality of windings; and wherein thespacing between adjacent windings of the plurality of windings increasesin a distal direction along the second filar region.
 10. The catheter ofclaim 9, further comprising a polymeric outer layer surrounding and incontact with the coil.
 11. The catheter of claim 10, wherein the one ormore filars are embedded in the polymeric outer layer in the secondfilar region.
 12. The catheter of claim 11, wherein the polymeric outerlayer contacts the tubular elongate shaft between adjacent windings ofthe plurality of windings in the second filar region.
 13. The catheterof claim 9, wherein the first filar region includes a first filar innerdiameter and the second filar region includes a second filar innerdiameter and wherein the first filar inner diameter is less than thesecond filar inner diameter.
 14. The catheter of claim 9, wherein thefirst filar region includes a first filar inner diameter and the secondfilar region includes a second filar inner diameter and wherein thefirst filar inner diameter is the same as the second filar innerdiameter.
 15. The catheter of claim 9, wherein the coil has a firstouter diameter at the first position along the first filar region, andwherein the coil has a second outer diameter less than the first outerdiameter at the second position along the second filar region.
 16. Thecatheter of claim 9, wherein the second centroid is positioned radiallycloser to the tubular elongate shaft than the first centroid.
 17. Acatheter comprising: a tubular elongate shaft having a distal region anda lumen extending therethrough; a coil extending along the distal regionof the tubular elongate shaft, wherein the coil is formed from aplurality of filars wrapped around the tubular elongate shaft; whereinthe coil has a first filar region and a second filar region, the firstfilar region extending to a proximal end of the coil, and the secondfilar region extending to a distal end of the coil; wherein each filarof the plurality of filars has a first cross-sectional diameter alongthe first filar region and a second cross-sectional diameter along thesecond filar region, the second cross-sectional diameter being less thanthe first cross-sectional diameter; wherein each filar of the pluralityof filars has a cross-sectional area having a first centroid at a firstposition along the first filar region and a cross-sectional area havinga second centroid at a second position along the second filar region,the second centroid being positioned closer to a central longitudinalaxis of the tubular elongate shaft than the first centroid; wherein thecoil has a first spacing between adjacent filars in the first filarregion and the coil has second spacing between adjacent filars in thesecond filar region that is greater than the first spacing; and whereinthe second spacing increases in a distal direction along the secondfilar region; wherein the centroids of adjacent windings of theplurality of filars are equally spaced along an entire length of thecoil.
 18. The catheter of claim 17, wherein the second cross-sectionaldiameter decreases in a distal direction along the second filar region.19. The catheter of claim 17, wherein the coil has a first outerdiameter along the first filar region and a second outer diameter alongthe second filar region, the second outer diameter being less than thefirst outer diameter.